1. Field of the Invention
This invention relates, in general, to photocopying and, more specifically, to cleaning devices for removing residual toner from film photoconductors.
2. Description of the Prior Art
Cleaning toner from photosensitive members, or photoconductors, in copiers, printers, and like devices is one of the necessary functions usually performed in such apparatus. A toner cleaning station is usually located after the transfer of the developed image to the paper, transparency, or intermediate transfer member to remove any residual toner on the photoconductor after the transfer. Because of the many different types of machine configurations and processes used, there are many different types of toner cleaning devices which are constructed to offer certain advantages over other types of toner cleaning devices.
One main criteria in toner cleaning apparatus is to maintain adequate cleaning without scratching, scraping, marking, or otherwise degrading the surface of the photoconductor. One workable solution to the problem has been to keep the toner cleaning apparatus from touching the image side of the photoconductor. While this preserves the surface of the photoconductor and enhances its useful life, adequate cleaning with this type of system is sometimes difficult to achieve. Another requirement desired in cleaning apparatus is that it provide uniform cleaning action across the entire width of the photoconductor. With some types of cleaning systems, it is required that special arrangements of multiple cleaning devices be used across the photoconductor to provide the desired uniformity. This complicates the apparatus and can lead to manufacturing and service problems.
Other forms of cleaning apparatus have used a combination of cleaning devices which interact in the cleaning operation so that excessive force, mechanical or electrical, is not applied to the photoconductor. By using such combinations of devices, no one type of cleaning device significantly affects the surface of the photoconductor. This allows the photoconductor to be used for a large number of image transfer operations and machine life and economy are improved.
Film or web photoconductors are flexible and present special problems and solutions to film cleaning. U.S. Pat. No. 4,111,546, issued on Sept. 5, 1978, shows a cleaning system which, according to the patent text, can be used in film cleaning applications. This device uses a vibrating member on one side of the photoconductor and a brush cleaner-vacuum chamber system on the image side of the photoconductor. U.S. Pat. No. 3,965,478, issued on June 22, 1976, shows the use of a transducer on the inside of the photoconductor and a toner collection bin on the image side of the photoconductor to catch toner which falls from the photoconductor. Rather than removing toner after image transfer, this system is used to enhance the image quality before transfer by insuring that the proper toner particles are concentrated in the appropriate areas.
Therefore, it is desirable, and an object of this invention, to provide a non-destructive, uniform, cleaning device which is useful for removing residual toner from the image surface of a film photoconductor.